The present invention relates to the field of systems and apparatus for facilitating manual and/or mechanized work operations (e.g., assembly operations) on a work piece or product supported on a carrier and, more specifically, to an accumulator or buffer unit for accumulating a plurality of such carriers at a selected location along a production line, especially of the type formed by two or more modular units disclosed and claimed in commonly-assigned copending application U.S. Ser. No. 175,249 entitled "Modular Production Line Unit and System" filed on even date herewith by Irving Erlichman.
The modular units each include a low cost commercially available work table having a laminated hardwood table top measuring approximately 72".times.28".times.2.5" with an upwardly facing work surface; at least one work station where any one or more of a variety of work operations may be performed on the product; a self-contained endless conveyor, preferably having a major lower portion thereof recessed below the work surface, being continuously movable along a horizontally extending closed loop path during the performance of work operations for transporting a plurality of carriers in sequence to and away from the work station; and a carrier handling system at each work station for disengaging a carrier from the conveyor, locating and locking it at a fixed work position above the conveyor to facilitate assembly operations and for thereafter reengaging the carrier with the conveyor for transport away from the work station.
Each of the modular units also includes a pair of roller assemblies recessed into opposite ends of the table top, adjacent a front edge thereof, so that their upper roller surfaces are flush with the carrier supporting surface of the conveyor. When the modular units are arranged serially in end-to-end relation, the facing roller assemblies on successive units are in operative alignment and form a low friction path across the interface for facilitating carrier movement from the conveyor on one unit to the conveyor of the next successive unit in the line. Also provided on each units is a guide bar for deflecting a carrier off of the conveyor so that its momentum carries it across the aligned rollers to the next conveyor.
On most production lines it is desirable to provide accumulator or buffer units at selected points along the line for diverting the flow of carriers from the normal path connecting successive work stations. One function of such an accumulator is to temporarily delay the supply of carriers to the next work station so that the operator thereat may take a short scheduled work break or to allow adjustment or repair of assembly equipment thereat.
The modular units disclosed and claimed in the above-noted copending application also preferably include another pair of roller assemblies adjacent a rear edge of the table, and appropriate corresponding guide bars, for facilitating the advancement of carriers from that unit onto one accumulator and/or for facilitating the advancement of a carrier from another preceding accumulator onto the conveyor. In this case the deflector is mounted for movement between a deflecting position for deflecting carriers to the next successive unit or a non-deflecting position allowing the conveyor to advance the carrier toward the rear of the table where the corresponding guide bar deflects it off of the conveyor and it passes over the roller assembly thereat and then onto an accumulator.
While there are many types of accumulators known in the prior art, they tend to be mechanically complex and expensive. Also these accumulators tend to be of the dedicated type that is specifically designed for a particular product and/or a particular dedicated production line. As a result such accumulators may not be able to be used again if the product goes out of production earlier than planned or its design is radically changed thereby incurring an economic loss. Additionally, accumulators known in the prior art generally are not compatible with the particular modular units described above.
Therefore, it is an object of the invention to provide a simply constructed and low cost accumulator to use on a production line.
It is another object to provide such an accumulator that is compatible for use on a production line formed by the modular units of the type described above.
It is yet another object to provide such an accumulator that is specifically configured for use with carriers of the type having a standardized base section that is compatible with the conveyor and work station components of such a modular unit.
Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.